/*!
    \file  main.c
    \brief TIMER1 external trigger demo

    \version 2019-6-5, V1.0.0, firmware for GD32VF103
*/

/*
    Copyright (c) 2019, GigaDevice Semiconductor Inc.

    Redistribution and use in source and binary forms, with or without modification, 
are permitted provided that the following conditions are met:

    1. Redistributions of source code must retain the above copyright notice, this 
       list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright notice, 
       this list of conditions and the following disclaimer in the documentation 
       and/or other materials provided with the distribution.
    3. Neither the name of the copyright holder nor the names of its contributors 
       may be used to endorse or promote products derived from this software without 
       specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
OF SUCH DAMAGE.
*/

#include "gd32vf103.h"
#include <stdio.h>
#include "gd32vf103v_eval.h"

/* configure the GPIO ports */
void gpio_config(void);
/* configure the TIMER peripheral */
void timer_config(void);

/**
    \brief      configure the GPIO ports
    \param[in]  none
    \param[out] none
    \retval     none
  */
void gpio_config(void)
{
    rcu_periph_clock_enable(RCU_GPIOA);
    rcu_periph_clock_enable(RCU_AF);

    /*configure PA2(TIMER1 CH2) as alternate function*/
    gpio_init(GPIOA, GPIO_MODE_AF_PP, GPIO_OSPEED_50MHZ, GPIO_PIN_2);

    /*configure PA0(TIMER1 CH0) as alternate function*/
    gpio_init(GPIOA, GPIO_MODE_IN_FLOATING, GPIO_OSPEED_50MHZ, GPIO_PIN_0);
}

/**
    \brief      configure the TIMER peripheral
    \param[in]  none
    \param[out] none
    \retval     none
  */
void timer_config(void)
{
    /* TIMER with an external trigger -------------------------------------
    TIMER1 is configured as slave timer for an external trigger connected
    to TIMER1 CI0 pin :
    - The TIMER1 CI0FE0 is used as trigger input
    - rising edge is used to start the TIMER1: event mode.
    - TIMER1 CH2 is used PWM Mode 0.
    the starts of the TIMER1 counter are controlled by the 
    external trigger.  
    -------------------------------------------------------------------- */
    timer_oc_parameter_struct timer_ocinitpara;
    timer_parameter_struct timer_initpara;
    timer_ic_parameter_struct timer_icinitpara;

    rcu_periph_clock_enable(RCU_TIMER1);

    timer_deinit(TIMER1);
    /* initialize TIMER init parameter struct */
    timer_struct_para_init(&timer_initpara);
    /* TIMER1 configuration */
    timer_initpara.prescaler         = 239;
    timer_initpara.alignedmode       = TIMER_COUNTER_EDGE;
    timer_initpara.counterdirection  = TIMER_COUNTER_UP;
    timer_initpara.period            = 7999;
    timer_initpara.clockdivision     = TIMER_CKDIV_DIV1;
    timer_initpara.repetitioncounter = 0;
    timer_init(TIMER1, &timer_initpara);

    /* initialize TIMER channel output parameter struct */
    timer_channel_output_struct_para_init(&timer_ocinitpara);
     /* CH2 configuration in OC PWM0 mode */
    timer_ocinitpara.ocpolarity   = TIMER_OC_POLARITY_HIGH;
    timer_ocinitpara.ocnpolarity  = TIMER_OCN_POLARITY_HIGH;
    timer_ocinitpara.outputstate  = TIMER_CCX_ENABLE;
    timer_ocinitpara.outputnstate = TIMER_CCXN_DISABLE;
    timer_ocinitpara.ocidlestate  = TIMER_OC_IDLE_STATE_LOW;
    timer_ocinitpara.ocnidlestate = TIMER_OCN_IDLE_STATE_LOW;
    timer_channel_output_config(TIMER1, TIMER_CH_2, &timer_ocinitpara);

    timer_channel_output_pulse_value_config(TIMER1,TIMER_CH_2,3999);
    timer_channel_output_mode_config(TIMER1, TIMER_CH_2, TIMER_OC_MODE_PWM0);
    timer_channel_output_shadow_config(TIMER1, TIMER_CH_2, TIMER_OC_SHADOW_DISABLE);

    /* initialize TIMER channel input parameter struct */
    timer_channel_input_struct_para_init(&timer_icinitpara);
    /* TIMER1 CH0 input capture configuration */
    timer_icinitpara.icpolarity  = TIMER_IC_POLARITY_RISING;
    timer_icinitpara.icselection = TIMER_IC_SELECTION_DIRECTTI;
    timer_icinitpara.icprescaler = TIMER_IC_PSC_DIV1;
    timer_icinitpara.icfilter    = 0x02;
    timer_input_capture_config(TIMER1, TIMER_CH_0, &timer_icinitpara);

    /* slave mode selection: TIMER1 */
    /* TIMER1 input trigger: external trigger connected to CI0 */
    timer_input_trigger_source_select(TIMER1, TIMER_SMCFG_TRGSEL_CI0FE0);
    timer_slave_mode_select(TIMER1, TIMER_SLAVE_MODE_EVENT);

    /* auto-reload preload enable */
    timer_auto_reload_shadow_enable(TIMER1);
}

/*!
    \brief      main function
    \param[in]  none
    \param[out] none
    \retval     none
*/
int main(void)
{
    gpio_config();
    timer_config();

    while (1);
}
